<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div>*:nth-child(2) {
            font-weight: bold;
        }
    </style>
</head>

<body>
    <div class="content">
        <div>
            <span>你好1</span>
            <span>你好2</span>
            <span>你好3</span>
        </div>
        <p>
            <span>你好1</span>
            <span>你好2</span>
            <span>你好3</span>
        </p>
        <div>
            <p>你好1</p>
            <p>你好2</p>
            <p>你好3</p>
        </div>
    </div>
</body>

</html>